Wide-mouth pathway of flo-top collector permits capillary blood to flow freely into tube, minimizing chance of premature clotting in collection top. The unique �twist-assist� MICROGARD closure significantly reduces blood splatter upon removal, in comparison with other tube closures. 200-400 micro-liter capacity. Made of break-resistant plastic.- Tube, Sodium Fluoride, Na2EDTA, Microgard Closure, 50/bx, 4 bx/cs (Temp Sensitive; Non-Returnable)